Motorized toothbrush

ABSTRACT

A motorized toothbrush comprising a motor disposed within an interior chamber of a handle member. A drive shaft is in communication with the motor, its distal end having a drive gear thereon. A brush head is secured to the handle member, having three brush assemblies disposed therein, each brush assembly including a base gear disposed within the cover, and a bristle block disposed above the cover. Each of the base gears are engaged with the adjacent base gears of the other brush assemblies, and the drive gear is engaged with the first base gear. When the motor rotates the drive shaft, the first base gear rotates the first bristle block in a first direction, which causes counter-rotation of the second base gear and bristle block, which causes the third base gear and bristle block to rotate in the first direction.

FIELD

The present invention relates generally to a motorized toothbrush and methods of use for providing superior cleaning to teeth and improving dental hygiene.

BACKGROUND

A traditional toothbrush includes a rigid handle having a brush head at one end, the brush head containing numerous tufts of closely-spaced bristles, normally made from nylon or similar synthetic fibers, and/or natural animal hair. An abrasive and/or antiseptic gel or paste can be applied to the bristles, and the brush is manually moved along the surfaces of the teeth using the handle. To facilitate effective dental cleaning, improvements to the toothbrush have included variations in the height and shape of blocks of bristles, the composition of the bristles, the shape or flexibility of the handle to facilitate access to all dental surfaces, and similar structural modifications.

The modernization of the toothbrush led to the development of electrical toothbrushes, also called rotary toothbrushes, which utilize electrical power to cause a brush head to vibrate and/or oscillate. While electric toothbrushes are of particular use to individuals with orthodontic appliances/applications and persons with limited manual dexterity, due to the automatic movement of the bristles, most independent research indicates that existing electric toothbrushes perform only marginally better than a manual toothbrush. This fact has been a source of disappointment to consumers and dental professionals alike, due to the great expense of an electric toothbrush over the manual variety.

A need exists for a motorized toothbrush that can provide a combination of directional movements to multiple brush heads, enabling superior cleaning over conventional electric toothbrushes.

A need also exists for a motorized toothbrush that facilitates access to all dental surfaces within the mouth to ensure thorough and complete brushing and improved oral hygiene.

A further need exists for a motorized toothbrush that is simple in construction and design, minimizing excess parts, thereby providing a product that is efficient and inexpensive to manufacture.

The present invention meets these needs.

SUMMARY

The present invention relates generally to a motorized toothbrush that can provide a combination of rotational and counter-rotational movements to multiple brush heads, while utilizing a simple design with a minimum of moving parts.

The toothbrush includes a handle member having an interior chamber. The handle can be formed from plastic, metal, or another similar generally stiff, durable, water-resistant material able to form a seal sufficient to prevent water from entering the interior chamber. While the handle can have any shape or size, in an embodiment of the invention, the handle can be generally cylindrical in shape, having a length of about 4.750 to 5.500 inches and a diameter of about 0.600 to 0.750 inches. The handle can include exterior gripping elements, such as knurling, rubber or polymer pads or strips, or similar elements to facilitate carrying and maneuvering of the toothbrush within the mouth.

A motor is disposed within the interior chamber. The motor can include any type of electrical motor small enough to fit within the interior chamber, and sufficiently powerful to rotate an attached drive shaft, such as a 1.5 volt, 1 amp motor. In an embodiment of the invention, a power source can also be disposed within the interior chamber. The motorized toothbrush can be adapted to utilize any type of power source, and any combination of usable power sources, such as one or more rechargeable or replaceable batteries, which can include typical “AA” or “AAA” batteries, a lithium ion battery, or similar power sources. The toothbrush can include contacts and circuitry to enable engagement with a charger adapted to recharge one or more rechargeable batteries within. The motorized toothbrush can also include contacts, sockets, and circuitry to enable the motor to be powered using alternating current, such as a transformer adapter.

A drive shaft is disposed in communication with the motor, such that the motor causes the drive shaft to rotate when actuated. The drive shaft includes a drive gear at its distal end remote from the motor.

A replaceable brush head can be secured to the handle member. The brush head can be interchangeable to facilitate replacement when a brush head becomes worn or damaged, or to enable use of differing configurations and types of bristles. The brush head can include a cover adapted for securing to the handle proximate to the drive shaft, the cover having openings for accommodating brush assemblies. The cover can be made from the same materials as the handle, or a similar material, and can be of any size able to attach to the handle at one end, and comfortably fit and maneuver within the mouth at the opposing end. In an embodiment of the invention, the cover can have an overall length of about 3.250 to 3.500 inches, with a neck member having a length of about 1.875 to 2.125 inches and a head member having a length of about 1.125 inches to 1.500 inches. The width and thickness of the cover can vary depending on the configuration and size of the attached bristles.

The handle, the cover, or combinations thereof, can include a chamber containing a liquid and/or a gas that can be provided to the bristle blocks during use. For example, a chamber within the handle containing antiseptic liquid can be squeezed during brushing to transport the antiseptic liquid through a valve to the bristles, where it can be spread throughout the mouth. Similarly, the chamber could contain air and blow the air into the mouth when squeezed, for facilitating cleaning between adjacent teeth by blowing air and/or flowing toothpaste through interdental spaces.

Three brush assemblies are disposed through adjacent openings in the cover. Each brush assembly includes a base gear disposed beneath the cover and a bristle block protruding through the respective opening in the cover for use contacting dental surfaces. The drive gear of the drive shaft is engaged with the base gear of the first brush assembly. The base gear of the second brush assembly is engaged with that of the first brush assembly. Likewise, the base gear of the third brush assembly is engaged with that of the second brush assembly. Use of three brush assemblies facilitates access of the bristles to all dental surfaces, including back surfaces of the teeth, and the rearmost molars.

When the motor causes the drive shaft to rotate, the drive shaft transfers motion to the first base gear, causing rotation of the first bristle block. The rotation of the first base gear causes the second base gear to rotate in the opposing direction, providing counter-rotational movement to the second bristle block. The counter-rotation of the second base gear causes the third base gear to rotate in the initial direction, causing rotation of the third bristle block. Counter-rotational movement of adjacent bristle blocks provides superior cleaning to dental surfaces when compared with conventional rotary toothbrushes.

In an embodiment of the invention, one or more additional base gears can be disposed between brush assemblies, such as when it is desirable to utilize a brush head having space between adjacent bristle blocks, or when it is desirable to utilize a brush head that does not provide opposing counter-rotational movement between each set of adjacent bristles. For example, movement of the first base gear could cause rotation of an additional base gear engaged with the first base gear, which would in turn cause rotation of the second base gear engaged with the additional base gear in the same direction as the first base gear. Through this embodiment of the invention, one or more base gears could be selectively configured to rotate in the same direction as one or more adjacent base gears.

In a further embodiment of the invention, one or more switches can be included, in communication with the motor, for enabling a user to selectively cause the motor to rotate the drive shaft in a clockwise or counterclockwise direction. Use of switches can thereby enable a user to selectively cause rotation of the bristles to reverse, enabling a user to manually cause alternating, oscillating rotation to provide improved cleaning ability. In addition to forward and reverse directions, switches can be used to enable automatic alternating forward and reverse movements of the drive shaft, providing the bristles with automatic, slow or rapid, oscillating rotational movements. Additionally, switches can be used to enable axial, pivotal, and/or vibrational motion.

Along the drive shaft, a cam can be included, for providing non-rotational motion to the brush head. For example, the cam can include a first portion secured to the drive shaft that rotates concurrent with the drive shaft, while a second portion in communication with the brush head slidably moves along the drive shaft. A biasing member, such as a spring, can bias the second portion into engagement with the first portion, such that rotation of the first portion moves the second portion outward briefly, until the biasing member causes the return of the second portion into engagement with the first portion, thereby causing back-and-forth, axial movement of the brush head.

The brush head can be flexibly and/or pivotably mounted to the drive shaft, for enabling horizontal and/or vertical pivoting of the brush head during use. Other types of movement can also be selectable, such as utilizing a motor adapted for providing vibration to the brush head, in addition to imparting movement to the bristle blocks. Through the above embodiments of the invention, the present motorized toothbrush is thereby able to provide the bristles of the brush head with rotational movement, counter-rotational movement, oscillating movement, axial movement, vibrational movement, horizontal and vertical pivoting movement, or combinations thereof. The embodied combinations of rotational and non-rotational movement of the bristles provide enhanced performance over conventional electric toothbrushes.

The present invention also relates to a method for cleaning teeth that includes providing a brush head, as described previously, having three brush assemblies with bristle blocks disposed atop base gears engaged with one another, placing the bristles against the teeth, and applying force to the first base gear, such as through use of a motor. Rotation of the first base gear and attached first bristle block causes counter-rotation of the second base gear and second bristle block in the opposite direction, which causes rotation of the third base gear and third bristle block in the original direction.

The method can further include applying non-rotational force to the brush head to axially and/or laterally move the brush head, which can include use of a cam assembly, as described previously. The brush head can be horizontally pivoted during use, such as through use of a pivotable connection between the brush head and the handle.

In an embodiment of the invention, the rotational force applied to the first base gear can be selectively or automatically reversed, to enhance the effectiveness of the cleaning. In a further embodiment of the invention, a liquid and/or gas can be provided to the brush head during use, such as by transmitting the liquid from an enclosed chamber within or in communication with the brush head.

The embodied toothbrush and method of use thereby provide a combination of directional movements to multiple bristle blocks, thereby enabling improved oral hygiene. The embodied toothbrush also facilitates access to all dental surfaces, and provides a design that is simple, efficient, and inexpensive to construct.

BRIEF DESCRIPTION OF THE DRAWINGS

In the detailed description of the embodiments of the invention presented below, reference is made to the accompanying drawings, in which:

FIG. 1A depicts a top view of an embodiment of the present motorized toothbrush.

FIG. 1B depicts a side view of the motorized toothbrush of FIG. 1A.

FIG. 1C depicts a bottom view of the motorized toothbrush of FIG. 1A.

FIG. 1D depicts a side view of the motorized toothbrush of FIG. 1A having a differing brush head.

FIG. 1E depicts a cross-sectional view of the motorized toothbrush of FIG. 1A having a differing brush head.

FIG. 2 depicts an exploded perspective view of an alternate embodiment of the present motorized toothbrush.

FIG. 3A depicts an exploded perspective view of another embodiment of the present motorized toothbrush.

FIG. 3B depicts an exploded perspective view of the motorized toothbrush of FIG. 3A having a differing brush head and an additional moving part for providing vibrational motion to the brush head.

FIG. 4 depicts a cross-sectional view of another possible embodiment of the present motorized toothbrush.

The depicted embodiments of the invention are described below with reference to the listed Figures.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Before explaining the present embodiments in detail, it is to be understood that the embodiments are not limited to the particular descriptions and that the embodiments can be practiced or carried out in various ways.

Referring now to FIGS. 1A, 1B, and 1C, an embodiment of the present motorized toothbrush is depicted. The toothbrush is shown having a handle (10), which is depicted as generally cylindrical in shape, having a length of about 4.750 inches and a diameter of about 0.750 inches. Other shapes and dimensions are also usable. For example, a smaller handle could be utilized for a toothbrush intended for a child, while a wider handle or a handle having a shape adapted to facilitate gripping could be utilized for individuals lacking manual dexterity.

The handle (10) contains an interior chamber containing a motor therein, and in an embodiment, one or more power sources (not visible in FIGS. 1A, 1B, and 1C). The handle (10) is depicted having an end cover (12) attached thereon, which can be usable to control access to batteries or other power sources within the handle (10), and can retain batteries against internal electrical contacts. The end cover (12) can include appropriate electrical contacts and/or springs to enable powering of the motorized toothbrush using one or more selected types of batteries. The depicted motorized toothbrush could also be adapted to utilize alternating current or other power sources, and the end cover (12) can be usable to access the internal contacts, circuitry, wiring, motor, or other components for repair and/or replacement. In an embodiment, the end cover (12) can have a width of about 0.313 inches and a diameter equal to that of the handle (10).

The handle (10) is also depicted having a switch (14), shown in FIGS. 1A and 1B, disposed thereon, which is usable to control the motor disposed within the handle (10). The depicted switch (14) is shown having three possible positions for activating the motor in a first direction, activating the motor in a second direction opposite the first direction, and for deactivating the motor. Switches having other possible settings for the motor, such as actuating vibrational motion and/or oscillating forward and reverse rotational motion, or other types of rotational and non-rotational motion, are also usable, depending on the configuration of the motor disposed within the handle (10) and that of the brush head (16) attached to the handle (10).

The handle (10) is further shown having an access screw (32), shown in FIG. 1C, disposed on the underside, which is usable to remove a portion of the body of the handle (10) to enable access to the contained motor, power source, or other components located within for repair and/or replacement. In an embodiment of the invention, the handle (10) can be a one-piece construction, or the handle (10) can be a multi-part construction lacking a feature for enabling access to the contents of the handle (10). The present motorized toothbrush is simple and inexpensive to construct, therefore, replacement and repair of internal components can be unnecessary.

A brush head (16) is depicted removably attached to the handle (10). The brush head (16) is shown having a bristle carrier (18), a neck (20), and an attachment end (22). The attachment end (22) can be releasably attached to the handle (10), such as through use of an internal hook, clasp, biased pin, or similar latching and/or locking mechanism. FIGS. 1A and 1B show the attachment end (22) having a release button (24), which is usable to remove the brush head (16) when worn, or when it is desirable to replace the brush head (16) with a brush head having a differing configuration of bristles. The attachment end (22) is depicted having a cylindrical shape, with a diameter equal to that of the handle (10), and a length of about 0.501 inches.

The neck (20) is shown as a tapered member extending between the attachment end (22) and the bristle carrier (18), having a length of about 1.624 inches. The bristle carrier (18) is depicted as an oblong diamond or oval shape having rounded ends, and is shown having a first bristle block (26), a second bristle block (28), and a third bristle block (30) disposed therethrough. The bristle carrier (18) can be a substantially hollow structure and can have a plurality of openings (not visible in FIG. 1A, 1B, or 1C) disposed on its top surface, with base gears (not shown) disposed within the bristle carrier (18), while the bristle blocks (26, 28, 30) attached to the base gears protrude through the openings, such that rotation of the base gears causes rotation of the bristle blocks (26, 28, 30). The bristle carrier (18) is depicted having a length of about 1.125 inches, a width of about 0.500 inches, and a thickness of about 0.333 inches. A bristle carrier having other dimensions is also usable, such as when bristle blocks of specific sizes, shapes, and/or configurations require a bristle carrier of a certain size or shape.

While differing bristle block shapes and configurations are possible, FIGS. 1A and 1B depict each bristle block (26, 28, 30) as generally cylindrical in shape. The first and third bristle blocks (26, 30) are shown having a diameter of about 0.312 inches, with a sloped top surface that tapers downward toward the second bristle block (28), having a maximum height of about 0.755 inches. The second bristle block (28) is shown having a slightly larger diameter that that of the first and third bristle blocks (26, 30), the depicted diameter being about 0.391 inches. Other shapes, sizes, and configurations of bristles are also usable.

Referring to FIG. 1D, a side view of the motorized toothbrush of FIG. 1A is shown, having a differing brush head (16) attached thereon. The depicted brush head (16) is shown having a first bristle block (26) and a third bristle block (30), each angled toward a second central bristle block (28). The first and third bristle blocks (26, 30) are shown having an angled top surface of about 25 degrees, however any angle or other configuration can be usable to facilitate access to all dental surfaces. The central bristle block (28) is shown angled toward the first bristle block (26) at an angle of approximately 20 degrees, though any angle or other configuration can be used to improve the ability of the bristle blocks (26, 28, 30) to effectively clean dental surfaces.

Referring now to FIG. 1E, a cross-sectional view of the motorized toothbrush of FIG. 1A is shown, having a differing brush head (16) attached thereon, with bristle blocks (26, 28, 30) having angled top surfaces for facilitating access to all dental surfaces. The brush head (16) is shown attached to the handle (10), having a release button (24) for facilitating removal and replacement of the brush head (16). The handle (10) is shown containing two power sources (11 a, 11 b), secured within the handle by the end cap (12), which forms a threaded engagement (13) with the handle (10). The power sources (11 a, 11 b), provide power to a motor (15), which is coupled to a drive shaft (17) to provide rotational movement to the drive shaft (17). Each bristle block (26, 28, 30) is supported by a base gear (27, 29, 31). Each of the base gears (27, 29, 31) is engaged with each adjacent base gear. The drive shaft (17) has a gear on its distal end for engagement with the third base gear (31). Rotation of the drive shaft (17) causes the third base gear (31) and third bristle block (30) to rotate in a first direction, which causes the second base gear (29) and second bristle block (28) to rotate in the opposite direction. Rotation of the second base gear (29) causes the first base gear (27) and first bristle block (26) to rotate in the first direction.

Referring now to FIG. 2, an exploded perspective view of an alternate embodiment of the present motorized toothbrush is shown. The toothbrush includes a handle (34), which is shown having a front housing member (36) and a rear housing member (38). The housing members (36, 38) are each depicted having an elongated concave shape, such that when connected together, the handle (34) is provided with the shape of a hollow cylinder having a diameter of about 0.625 inches, defining an interior chamber (40). While FIG. 2 depicts two housing members (36, 38), in an embodiment of the invention, the handle (34) can be a one-piece construction, having a singular housing section.

The interior chamber (40) is shown containing a motor (42), which is powered by a first power source (44), and a second power source (46), which FIG. 2 depicts as AAA batteries. A positive lead (48), such as a brass button or similar electrical contact, can be disposed on the surface of the motor (42) for contacting the first power source (44). A negative lead (50), which is shown as a ground spring, can be disposed opposite the positive lead (48) in contact with the second power source (46). A cap (52), can be engaged with the housing members (36, 38), such as through use of complementary threads, to enclose the interior chamber (40) and secure the power sources (44, 46) against the leads (48, 50).

The toothbrush is also shown including brush head (54), having a neck member (55) and a head portion (57), defined by attachment of a two-part hollow cover having a front cover housing member (56) and a back cover housing member (58). While two cover housing members (56, 58) are shown, in an embodiment of the invention, the brush head can include a one-piece cover. While the dimensions of the depicted motorized toothbrush can be varied, depending on the brush assemblies that are accommodated, the head portion (57) is shown having a length of about 1.375 inches and a width of about 0.492 inches. The head portion (57) is further shown having a first opening (60), a second opening (62), and a third opening (64) disposed therethrough, for accommodating bristles (not shown in FIG. 2) from brush assemblies disposed within the back cover housing member (58). The openings (60, 62, 64) are depicted as round holes of approximately 0.375 inches in diameter, however the openings (60, 62, 64) can have differing sizes, such as for accommodating bristle blocks of differing diameters.

Within the back cover housing member (58), a first base gear (66) is shown. A second base gear (68) is depicted engaged with the first base gear (66), and a third base gear (70) is shown engaged with the second base gear (68). A drive shaft (72) is engaged with the motor (42) via a coupler (74), and extends between the motor (42) and the first base gear (66). The drive shaft (72) is shown having a drive gear (76) on the end opposite the motor (42). The drive gear (76) is engaged with the first base gear (66), such that as the motor (42) rotates the drive shaft (72) and drive gear (76), the first base gear (66) is rotated. The rotation of the first base gear (66) causes the second base gear (68) to rotate in the opposite direction, which in turn causes the third base gear (70) to rotate in the same direction as the first base gear (66). Bristles attached to the base gears (66, 68, 70) thereby rotate in opposition to adjacent bristles.

The handle (34) is shown having a first switch (77) and a second switch, (78) disposed thereon for controlling the motor (42). In an embodiment, the first switch (77) can be used to actuate the motor (42) in a first direction, such that the first and third base gears (66, 70) rotate in a clockwise direction while the second base gear (68) rotates in a counterclockwise direction, while the second switch (78) can actuate the motor (42) to rotate the first and third base gears (66, 70) in a counterclockwise direction, while the second base gear (68) rotates in a clockwise direction. The depicted motorized toothbrush can thereby enable a user to selectively or alternatingly control the rotational direction of the bristles.

Referring now to FIG. 3A, an exploded perspective view of another embodiment of the present motorized toothbrush is shown. The toothbrush is shown having a handle base (80) and a handle cover (82), which can be attached to form a generally cylindrical handle having an interior chamber therein. The connecting edges of the handle base (80) and handle cover (82) can have mating, overlapping flanges to form a watertight seal for preventing contact between liquid and the contents of the handle. A threaded hole (84) is shown disposed through the handle base and cover (80, 82), for accommodating a screw or bolt to secure the handle base and cover (80, 82) together to form the handle.

The handle cover (82) is shown having a recession (86) for accommodating a switch plate (88) having a switch (90) disposed thereon. A motor (92) is shown disposed within the handle base (80), and can be actuated using the switch (90). In an embodiment of the invention, the switch (90) can be used to selectively actuate the motor (92) in a forward direction, a reverse direction, in alternating forward and reverse directions, to provide axial, vibrational, or other rotational and non-rotational movement, or combinations thereof.

Power sources (94 a, 94 b), which FIG. 3A depicts as AAA batteries, are also able to be disposed within the handle base (80) adjacent the motor (92). A positive electrical contact (96) can be secured within the handle base (80) in contact with the motor (92) and a first side of the power sources (94), while a negative electrical contact (98), which is depicted as a ground spring, can be disposed in contact with the opposing side of the power sources (94 a, 94 b). A ground guide (100) can be positioned between the positive and negative contacts (96, 98).

A threaded end cap (102) can be used to secure the power sources (94 a, 94 b) within the handle by engaging complementary threads (104) disposed within the end of the handle base (80) and handle cover (82). The negative electrical contact (98) can be severable from or integral with the end cap (102). While FIG. 3 depicts the thread cap (102) having exterior threads for engagement with the complementary interior threads (104) of the handle base (80), in an embodiment of the invention, the end cap (102) can be integral with the negative electrical contact (98) and can have interior threads for engagement with an end of the handle base (80) having exterior threads to provide a watertight seal.

FIG. 3A also depicts a brush base (105) and a brush cover (106), which can be attached to form a hollow brush head attachable to the handle. While a separate brush base and cover (105, 106) are shown, in an embodiment of the invention, the brush head can be formed from a single piece. The brush cover (106) has a head member (108) with three openings (110 a, 110 b, 110 c) disposed therethrough, for accommodating brush assemblies, each having bristle blocks (112 a, 112 b, 112 c) disposed atop base gears (114 a, 114 b, 114 c). The base gears (114 a, 114 b, 114 c) can be disposed beneath the brush cover (106) within the brush base (105), removably or fixedly secured atop gear pegs (116), enabling the gears to be rotated from beneath the brush cover (106), causing rotation of the bristle blocks (112 a, 112 b, 112 c) above the brush cover (106).

Two additional base gears (118 a, 118 b) are also shown, which can be disposed between the base gears (114 a, 114 b, 114 c) atop gear pegs (116) of the brush assemblies, for transferring motion therebetween. The differing base gears (114 a, 114 b, 114 c, 118 a, 118 b), gear pegs (116), openings (110 a, 110 b, 110 c), and bristle blocks (112 a, 112 b, 112 c) can each be identical to facilitate ease of assembly and design. In an embodiment of the invention, each brush assembly and corresponding bristle block, base gear, and/or gear peg can be sized differently. For example, the central base gear could have a diameter of 0.375 inches for accommodating a larger bristle block, while the two adjacent base gears could have a diameter of 0.3125 for accommodating two smaller bristle blocks, or other similar combinations of identically or differently sized bristle blocks. Additionally, the lengths, angles, and/or composition of the bristles can also be varied. For example, the outer bristle blocks could have taller bristles than the central bristle block, that are angled for assisting brushing of rear teeth and gingival areas. The tops of each bristle block could be angled to provide superior access to and cleaning of dental surfaces. In an embodiment of the invention, the outer bristle blocks could have top surfaces angled inward toward the center of the brush head at an angle 25 degrees, while the central bristle block is angled toward the top of the brush head at an angle 20 degrees. Other angles or configurations are also usable.

A drive shaft (120) is shown, connectable with the motor (92) using a square coupler (122), which mates with a male coupling end (124) of the drive shaft (120). Other coupling members are also usable, such as a hexagonal or other geometric coupler, depending on the shape and size of the drive shaft (120). The drive shaft (120) protrudes from the handle into the hollow brush head, where a drive gear (126) at the distal end of the drive shaft (120) engages the first of the base gears (114 a).

Referring now to FIG. 3B, the motorized toothbrush of FIG. 3A is shown, having a different brush head attached thereon, a body having an improved engagement between its upper and lower portions, a differing end cap, and an additional internal member for providing vibrational movement to the brush head.

Specifically, FIG. 3B depicts the handle base (80) having a staggered edge (162) for interlocking and overlapping with a complementary staggered edge (not visible in FIG. 3B) on the handle cover (82). The overlap between the staggered edges forms a superior engagement for preventing the entry of water, which can impair operation of the motor (92) and power sources (94 a, 94 b) contained within the handle. A conventional flat edge could potentially permit the entry of water or other liquids if submerged or otherwise exposed for a significant period of time. Conversely, the mating, overlapping flanges provided by the staggered edge (162) can form a sufficiently watertight seal.

A threaded end cap (102) is used to secure the power sources (94 a, 94 b) within the handle between the negative electrical contact (98) and the positive electrical contact (96). FIG. 3B depicts the end cap (102) having interior threads (158) for engaging exterior threads (160) at the proximate end of the handle cover (82) and handle base (80). Use of interior threads within the end cap (102) forms a secure, watertight engagement. The negative electrical contact (98), which is depicted as a ground spring, can be contained within the end cap (102). In an embodiment of the invention, a ground spring can be integral with the end cap (102).

FIG. 3B depicts an alternate brush base (105) from that depicted in FIG. 3A, the depicted brush base (105) having three gear pegs (116) disposed therein for insertion into three base gears (114 a, 114 b, 114 c). The first base gear (114 a) is shown supporting a first bristle block (112 a), which is shown having a top surface angled at approximately 25 degrees. The second base gear (114 b) is shown having a second bristle block (112 b) supported thereon, which is shown having a top surface angled at approximately 20 degrees. The third base gear (114 c) is shown having a third bristle block (112 c) supported thereon, which is shown having a top surface angled at approximately 25 degrees, in opposition to the angle of the first bristle block (112 a). This configuration of angled bristles can provide superior cleaning of all dental surfaces, however other angles and configurations of bristles are also usable.

Because the brush head depicted in FIG. 3B includes only three base gears (114 a, 114 b, 114 c), with no additional base gears disposed therebetween, rotation of the drive shaft (120) by the motor (92) can cause rotation of the third base gear (114 c) and third bristle block (112 c) in a first direction. Rotation of the third base gear (114 c) causes rotation of the second base gear (114 b) and second bristle block (112 b) in the opposite direction, which causes rotation of the first base gear (114 a) and first bristle block (112 a) in the same direction as the third base gear (114 c).

Additionally, FIG. 3B depicts a counterbalance (164) through which the drive shaft (120) is disposed. Engagement of the drive shaft (120) with the counterbalance (164) enables rotation of the counterbalance (164) concurrent with the drive shaft (120). Movement of the counterbalance (164) during rotation of the drive shaft (12) provides vibrational motion to the brush head, in addition to the rotational movement imparted by the drive shaft (120).

The brush cover (106) is shown having a hole (168) therethrough for enabling a release button (166) disposed on the handle cover (82) to protrude. The release button (166) is usable to remove and replace the brush head when the brush head becomes worn or when a differing configuration of bristles is desired.

Referring now to FIG. 4, a cross-sectional view of an alternate embodiment of the present motorized toothbrush is depicted. The toothbrush is shown having a hollow handle member (128) with an interior chamber (130) defined therein. A removable brush head (132) is attached to the handle member (128). The brush head (132) can have any configuration of bristles, including having three brush assemblies with engaged base gears, as described previously. Within the interior chamber (130) is a motor (134) in communication with a drive shaft (136). Also within the interior chamber (130) is a power source (138), which FIG. 4 depicts as a rechargeable AA battery. A positive electrical contact (140) is shown disposed in contact with the motor (134) and one end of the power source (138), while a negative electrical contact (142), depicted as a ground spring, is shown disposed at the opposing end of the power source (138). The motor can be actuated through use of one or more switches (not visible in FIG. 4).

A cam assembly is also disposed along the drive shaft (136). The cam assembly includes a fixed portion (141) secured to the drive shaft (136) proximate to the motor (134). A movable portion (143) of the cam assembly is slidably secured about the drive shaft (136) adjacent to the fixed portion (141). A biasing member (144), depicted as a spring, is disposed adjacent to the movable portion (143). As the motor (134) rotates the drive shaft (136), the fixed portion (141) is rotated concurrently, applying a lateral force (146) against the movable portion (143). The shape of the cam portions (141, 143) causes the lateral force (146) to impart an axial force (148) to the movable portion (143), which slides along the drive shaft (136) toward the brush head (132).

The brush head (132) is shown engaged with a shaft sleeve (150) disposed over the drive shaft (136), such that the axial force (148) of the movable portion (143) of the cam assembly causes the drive shaft (136) to move within the shaft sleeve (150), causing axial and lateral movement of the brush head (132) during use. The brush head (132) can be secured to the handle member (128) using a pivotable connection (152) to facilitate this non-rotational movement. The biasing member (144) imparts a reverse axial force (154) to return the movable portion (143) of the cam assembly to its original position, where the fixed portion (141) can again engage the movable portion (143) to cause non-rotational movement of the brush head (132).

A separate chamber (156) within the handle member (128) can be used to contain liquid, such as water, antiseptic liquid, toothpaste, or another fluid, which can be dispensed from the separate chamber (156) to the brush head (132) when actuated, such as by squeezing. One or more one-way valves or similar devices can be disposed between the separate chamber (156) and the brush head (132). While the separate chamber (156) is shown proximate to the brush head (132) and disposed about the shaft sleeve (150), a separate chamber (156) could be disposed at any location within or proximate to the handle member (128), depending on the configuration and arrangement of components within the motorized toothbrush.

The present embodiments thereby provide superior brushing ability when compared to existing motorized toothbrushes, through selective use of rotational, counter-rotational, oscillating, vibrating, axial, lateral, and/or pivoting movement. Further, the use of three brush assemblies facilitates reaching all dental surfaces within the mouth when brushing. Further, the present embodiments are simple in construction, using a minimum of moving parts, enabling the present motorized toothbrushes to be manufactured, maintained, and repaired efficiently and inexpensively.

While these embodiments have been described with emphasis on the embodiments, it should be understood that within the scope of the appended claims, the embodiments might be practiced other than as specifically described herein. 

1. A motorized toothbrush comprising: a handle member comprising an interior chamber; a motor disposed within the interior chamber; a drive shaft comprising a first end and a second end, wherein the first end is in communication with the motor, and wherein the second end comprises a drive gear; and a brush head comprising: a cover adapted for securing to the handle member proximate to the drive shaft, wherein the cover comprises a plurality of openings for accommodating brush assemblies; a first brush assembly comprising a first base gear secured to a first bristle block, wherein the first base gear is disposed within the cover, wherein the first bristle block is disposed external to the cover, and wherein the first base gear is engaged with the drive gear of the drive shaft; a second brush assembly comprising a second base gear secured to a second bristle block, wherein the second base gear is disposed within the cover, wherein the second bristle block is disposed external to the cover, and wherein the second base gear is engaged with the first base gear of the first brush assembly; and a third brush assembly comprising a third base gear secured to a third bristle block, wherein the third base gear is disposed within the cover, wherein the third bristle block is disposed external to the cover, and wherein the third base gear is engaged with the second base gear of the second brush assembly, wherein the motor imparts motion to the drive shaft, which transfers motion to the first base gear to cause rotation of the first brush assembly in a first direction, wherein the first base gear transfers motion to the second base gear to cause rotation of the second brush assembly in a second direction opposite the first direction, and wherein the second base gear transfers motion to the third base gear to cause rotation of the third brush assembly in the first direction.
 2. The motorized toothbrush of claim 1, wherein the brush head further comprises at least one additional base gear engaged with the first base gear, the second base gear, the third base gear, or combinations thereof.
 3. The motorized toothbrush of claim 1, further comprising a power source disposed within the interior chamber for providing power to the motor.
 4. The motorized toothbrush of claim 1, further comprising a switch in communication with the motor, wherein the switch selectively causes the motor to rotate the drive shaft in a clockwise direction or a counterclockwise direction, thereby enabling rotation of the brush assemblies in a selected direction.
 5. The motorized toothbrush of claim 1, wherein the handle, the cover, or combinations thereof, further comprise a chamber containing a liquid, a gas, or combinations thereof, in communication with the brush assemblies for providing the liquid, the gas, or combinations thereof to the bristle blocks during use.
 6. The motorized toothbrush of claim 1, further comprising a cam assembly disposed about the drive shaft for providing non-rotational motion to the brush head.
 7. The motorized toothbrush of claim 6, wherein the cam assembly comprises a first portion secured to the drive shaft and configured for rotational movement concurrent with the drive shaft, a second portion slidably movable along the drive shaft and configured for axial movement when engaged by the first portion, and a biasing member in communication with the second portion and the brush head for transmitting axial movement of the second portion to the brush head and biasing the second portion to engage the first portion.
 8. The motorized toothbrush of claim 1, wherein the brush head is pivotably mounted to the drive shaft for enabling horizontal pivoting of the brush head, vertical pivoting of the brush head, rotational pivoting of the brush head, or combinations thereof.
 9. The motorized toothbrush of claim 1, wherein the first bristle block comprises a first angled top surface having an angle ranging from 20 degrees to 30 degrees, wherein the second bristle block comprises a second angled top surface having an angle ranging from 15 degrees to 25 degrees, and wherein the third bristle block comprises a third angled top surface having an angle ranging from 20 degrees to 30 degrees.
 10. A method for cleaning teeth comprising the steps of: providing a brush head comprising a first brush assembly comprising a first base gear secured to a first bristle block, a second brush assembly comprising a second base gear secured to a second bristle block and engaged with the first base gear of the first brush assembly, and a third brush assembly comprising a third base gear secured to a third bristle block and engaged with the second base gear of the second brush assembly; positioning the brush head such that at least one of the bristle blocks is in contact with at least one tooth; and applying rotational force to the first base gear, thereby rotating the first bristle block in a first direction, wherein the first base gear transfers motion to the second base gear to cause rotation of the first brush assembly in a second direction opposite the first direction, and wherein the second base gear transfers motion to the third base gear to cause rotation of the third brush assembly in the first direction.
 11. The method of claim 10, wherein the step of applying rotational force to the first base gear comprises actuating a motor in communication with the first base gear.
 12. The method of claim 10, further comprising the step of applying non-rotational force to the brush head, thereby axially moving the brush head, laterally moving the brush head, or combinations thereof.
 13. The method of claim 12, wherein the step of applying non-rotational force to the first base gear comprises actuating a motor in communication with a cam assembly comprising a first portion configured for rotational movement, a second portion slidably configured for axial movement when engaged by the first portion, and a biasing member in communication with the second portion and the brush head for transmitting axial movement of the second portion to the brush head and biasing the second portion to engage the first portion, thereby causing engagement between the first portion and the second portion.
 14. The method of claim 10, further comprising the step of selectively reversing the rotational force applied to the first base gear, thereby rotating the first bristle block in the second direction, thereby rotating the second bristle block in the first direction, and thereby rotating the third bristle block in the second direction.
 15. The method of claim 10, further comprising the step of providing a liquid, a gas, or combinations thereof, to the brush head during use.
 16. The method of claim 15, wherein the step of providing the liquid, the gas, or combinations thereof, comprises transmitting the liquid, the gas, or combinations thereof, from an enclosed chamber in communication with the brush head.
 17. The method of claim 10, further comprising the steps of horizontally pivoting the brush head during use, vertically pivoting the brush head during use, rotationally pivoting the brush head during use, or combinations thereof, using a pivotable connection between the brush head and a handle.
 18. A motorized toothbrush comprising: a handle member comprising an interior chamber; a motor disposed within the interior chamber; a drive shaft comprising a first end and a second end, wherein the first end is in communication with the motor, and wherein the second end comprises a drive gear; and a brush head comprising: a cover adapted for securing to the handle member proximate to the drive shaft, wherein the cover comprises a plurality of openings for accommodating brush assemblies; a first brush assembly comprising a first base gear secured to a first bristle block, wherein the first base gear is disposed within the cover, wherein the first bristle block is disposed external to the cover, and wherein the first base gear is engaged with the drive gear of the drive shaft; a second base gear disposed within the cover and engaged with the first base gear; a second brush assembly comprising a third base gear secured to a second bristle block, wherein the third base gear is disposed within the cover, wherein the second bristle block is disposed external to the cover, and wherein the third base gear is engaged with the second base gear; a fourth base gear disposed within the cover and engaged with the third base gear; a third brush assembly comprising a fifth base gear secured to a third bristle block, wherein the fifth base gear is disposed within the cover, wherein the third bristle block is disposed external to the cover, and wherein the fifth base gear is engaged with the fourth base gear, wherein the motor imparts motion to the drive shaft, which transfers motion to the first base gear to cause rotation of the first brush assembly in a selected direction, wherein the first base gear transfers motion to the second base gear, wherein the second base gear transfers motion to the third base gear to cause rotation of the second brush assembly in the selected direction, wherein the third base gear transfers motion to the fourth base gear, and wherein the fourth base gear transfers motion to the fifth base gear to cause rotation of the third brush assembly in the selected direction.
 19. The motorized toothbrush of claim 18, further comprising a switch in communication with the motor, wherein the switch selectively causes the motor to rotate the drive shaft in a clockwise direction or a counterclockwise direction, thereby enabling selective rotation of the brush assemblies in a first selected direction or a second selected direction opposite the first selected direction.
 20. The motorized toothbrush of claim 18, wherein the brush head is pivotably mounted to the drive shaft for enabling horizontal pivoting of the brush head, vertical pivoting of the brush head, rotational pivoting of the brush head, or combinations thereof.
 21. The motorized toothbrush of claim 18, further comprising a power source disposed within the interior chamber for providing power to the motor.
 22. The motorized toothbrush of claim 18, wherein the first bristle block comprises a first angled top surface having an angle ranging from 20 degrees to 30 degrees, wherein the second bristle block comprises a second angled top surface having an angle ranging from 15 degrees to 25 degrees, and wherein the third bristle block comprises a third angled top surface having an angle ranging from 20 degrees to 30 degrees. 